Charles cuttriss



(No Model.)

O. GUTTRISS.

TELEPHONE.

No. 464,959. Patented Dec. 15,1891.

m I in B fl i'tnasa 66 f UNITED ST TES PATENT- OFFICE,

CHARLES CUTTRISS, OF NEW YORK, N. Y.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 464,959, dated December15, 1891.

Application filed July 22, 1891. Serial No. 400,279. (No model.)

To all whom it may concern:

Be it known that 1, CHARLES CUTTRISS, a subject of the Queen of GreatBritain, residing at New York, in the county and State of New York, haveinvented certain new and useful Improvements in Telephones, of which thefollowing is a specification, reference being had to the drawingsaccompanying and forming a part of the same.

This invention is an improvement in telephonic transmitters in which theundulations or changes in a current corresponding to the sound-waves ofarticulate speech are produced by the variations of the resistance of apart of the electric circuit due to the action thereon of a vibratingdiaphragm.

The invention consists, broadly, in the combination, with avibratingdiaphragm, of a resistant and resilient conductor included in thetransmitting-line or local circuit by the connection of its two endswith the diaphragm and a stationary terminal support, respectively, andwhich is bent or wound upon itself spirally in such manner that by thevibration of the diaphragm the convolutions will be closed uponthemselves and to a greater or less extent according to the amplitude ofthe vibrations, whereby that portion of the circuit including and formedby the resistant conductor will be shunted or short-circuited to acorrespondingly-varied degree and in accordance with the waves of thesounds impinging upon the diaphragm.

Specifically and in its preferred form my invention is embodied in atransmitter provided with a diaphragm, with which is arranged a spiralof carbon included in the circuit and secured to or held in contact withsaid diaphragm by an adjusting-screw or like device, so that thevibrations of the said diaphragm will be imparted to the spiralsubstantially in the direction of its central axis, whereby its spireswill be brought more or less into contact or into more or less intimatecontact with each other in accordance with the vibrations. Such atransmitter I have found to vbe exceedingly cheap and simple inconstruction, very efficient in its operation, easy of adjustment, andcapable of varied and extended use.

The invention is shown in detail in the accompanying drawings, in which?Figure 1 is a central sectional view of the instrument complete. Fig. 2is a View of the carbon spring or spiral detached from the instrument,and Fig. 3 is a central section of a modified form of the instrument.

A is a small box or case of ordinary description, provided at one endwith any suitable form of diaphragm B, by which I mean any such deviceas has been used in similar instruments for receiving the sound-wavesand imparting its vibration to the electrodes. In front of thisdiaphragm I have shown a mouthpiece C. In the rear of the case is abrass plug or block D, provided with a head d at its rear end. This plugis passed into a socket or recess in the rear end of the case A, itsforward end entering said case. A spiral spring E surrounds the plug andtends to force it outward or away from the diaphragm. This tendency iscounteracted and provision made for adjustment of the position of theplug by a set-screw F, placed in any suitable manner in the rear of theplug and bearing on its head.

Between the diaphragm B and the plug D, and, it may be, secured to both,is a carbon spiral G. I make this spiral by winding a carbonizable stripspirally around a suitable former ormandrel and carbonizing the same ina muffle in a manner similar to that followed in the manufacture ofcarbons for incandescent lamps. It may, however, be prepared in anyother way, it being only necessary that it should have a certain degreeof elasticity or resiliency, and so that under the influence of thevibrating diaphragm it may be compressed or bent so that'its spires, orin general different parts of its surface, may close upon themselves orbe forced into more intimate contact, whereby the resistance of thestrip as a whole will be varied in accordance with the vibrations of thediaphragm. The spiral may be composed of other materials, such as areknown in the art to be capable of producing the same or similar results,and it is desirable that it have a square or rectangular crosssection,in order to secure as broad and even a surface of contact as possiblebetween its difierent parts.

I may mention that I have produced excellent results by using a spiralcomposed of a carbonized strip of vulcanized fiber.

The connection with the usual local circuit is made to binding-posts Hand I, which are connected, respectively, with opposite ends of thespiral. The proper adjustment of this spiral is readily secured byturning the setscrew F to advance the plug D and close the spires or topermit the plug to recede and the spires to open.

It will be apparent from the nature of my invention that it is notlimited in any sense to the specific form of construction or arrangementwhiehI have shown for illustration. For instance, it is obvious that thefunction of the stationary support is to oppose the movement of thediaphragm. \Vhen, therefore, some such means of securing greateramplitude of vibrationsuch as doublediaphragrns-is employed, thestationary support is an imaginary point, for the diaphragms in suchcase move in opposite directions. I have illustrated this in Fig. 3, inwhich the case A is provided on opposite sides with diaphragms B and B.The ends of the carbon spiral are connected to the two diaphragms,respectively, so that when the sound-waves are directed into the casethrough a mouth-piece (J or are directed simultaneously against theexposed faces of both diaphragms the movements of both co-operate todistend and compress the spiral.

WVhat I claim is 1. In atelephonic transmitter, the combination, with adiaphragm, of a resilient resistant conducting-st-rip included in thecircuit by the connection of its two ends to the diaphragm and astationary terminal support,

2. The combination,'in a telephonic transmitter, with a vibratingdiaphragm, of a carbon spiral connected therewith and included in thecircuit, and adapted to be compressed and released by the movements ofvibration of said diaphragm. l

3. In a telephonic transmitter, the combination,with a vibratingdiaphragm and a stationary support, of a carbon spiral included in thecircuit and interposed between the diaphragm and the fixed support, asset forth.

4:. In a telephonic transmitter, the combina tion, With the diaphragmand a plug or block adjustable toward and from the same, of a carbonspiral interposed between the diaphragm and the adjustable plug andincluded in the electric circuit, as set forth.

5. The combination, in a telephonic transmitter, with the diaphragm anda stationary support, of a carbon spiral interposed between the same andformed of a strip square or rectangular in cross-section, as herein setforth.

CHARLES OUTTRISS.

Witnesses:

PARKER W. PAGE,

MAROELLA G. TRACY.

